1. Field of the Invention
The present invention is in the field of electronic imaging devices, specifically devices where the imaging effect is generated by mechanical scanning.
2. Description of the Related Art
Imaging devices of the kind with which the invention is concerned are applicable to detectors sensitive to any part of the spectrum, such as light, X-rays, sound and others.
In the following description and claims the term "detectors" is used for an electronic device which converts waves into electrical signals;
"mozaic detector" is used to describe a two dimensional detector built from a plurality of smaller detector arranged in rows and columns; PA1 "reconstructive tomography" is used to describe the mathematical process that combines data from multiple scanning apertures to generate images of a scanned area; and PA1 "zooming" is used to describe the effect where a small part of an image is magnified and displayed with the resolution originally used for the whole image. PA1 a detecting means sensitive to incoming signals; PA1 an image formation area where an image is created and which lies in front of the detecting means; PA1 a set of differently oriented scanning apertures that scan the image formation area; PA1 scanning means that scan the set of apertures in two directions; PA1 processing means that receive signals from the detector and reconstruct the image by means of reconstructive tomography or other mathematical processes. PA1 a rotating drum, in the perimeter of which a set of differently oriented apertures are mounted; PA1 motor means keyed to said rotating drum; PA1 detector means deployed after the drum; PA1 image formation area scanned by the drum & apertures assembly; PA1 second motor means perpendicularly keyed to the first motor drum assembly to provide a second rotational motion perpendicular to first rotational motion. PA1 the combination of the embodiment already disclosed with a controlling aperture mounted at the image formation plane; PA1 means for scaling up and down the size of the controlling aperture in the image formation plane. PA1 rotating disk on the front surface of which the set of differently oriented apertures are mounted; PA1 motor means keyed to the rotation disk; PA1 second motor means parallel keyed to the first motor disk assembly to provide a second rotation substantially parallel to first rotation and concentric with the image formation area; PA1 detecting means parallel to the image formation area.
Prior art imaging devices are based upon two major technologies.
One well known technique is using a mozaic detector as a sensitive element that converts light images into electronic signals and presents images to the user in a video format, as in a modern television.
The second technology is employed whenever mozaic detectors are technically impossible because of system complexity. This second technology employs single detectors, sensitive to a part of the spectrum range, in conjunction with a scanning mirror element that scans the image on the detector surface the detector generates electronic signals according to the part of the image lying on the detector surface at a specific moment. Special electronic circuitory is then used to transform the stream of signal into a video format.
On the other hand, non-imaging devices known as beam profilers are in use for measuring laser beams. Those devices use a precision blade that moves across a beam blocking light from reaching a photodetector element mounted behind the knife. For additional information, multiple knife edges each oriented in an different angle on a rotating drum move across a beam in a different direction as the drum rotates. Consequently during a rotation a set of data profiles is generated each representing the intensity profile in that direction.
This technique provides a way to generate a topographic and three dimensional low resolution intensity distribution of the incoming beam using reconstructive tomography.
Such a measuring device is disclosed in Melles Griot (company headquarters in California U.S.A.) catalog chapter 4. The catalog title is "Lasers and Instrumentation Guide." Other non imaging devices for beam profilers are disclosed in some Japanese patent applications, such as applications 1983-222404 and 60-7327. A technical review of that issue is presented in an article by John M. Fleisher and C. Breck Hitz under the title of "Gaussian Beam Profiling: How and Why" published in Lasers & Optronics in May 87.
The above-described devices are not applicable for imaging purposes because of their low resolution and small number of possible scans. Moreover, prior art technologies have great difficulties in zooming into an area of interest. This zooming effect is usually performed by optical special lenses or optical magnification.
It is the object of the present invention to provide an imaging system based on reconstructive tomography capable of detecting and creating an image and sensitive broad spectrum of different wavelengths implementing a non-optical, novel zooming mechanism superior to prior art devices.